Heat exchanger and method of manufacturing the same

ABSTRACT

A heat exchanger has a core including a plurality of tubes and a container disposed at an end of the core. The container has a tubular part and a cap part closing an end of the tubular part and defining a hole. The heat exchanger further has a pin for positioning. The pin extends through the hole of the cap part and to an outside of the container. The pin is bonded to the cap part with a brazing material. Further, the heat exchanger has a preliminary fixing portion by which the pin and the cap part are preliminarily fixed to each other before being bonded with the brazing material.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2005-348488 filed on Dec. 1, 2005, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a heat exchanger having a positioning pin and a method of manufacturing the same.

BACKGROUND OF THE INVENTION

It is known to provide a heat exchanger for a vehicle with positioning pins for positioning to a vehicle body. In a heat exchanger disclosed in Japanese Utility Model Laid-Open No. 6-74878, for example, headers are connected to both ends of flat tubes, and a cap is fixed to an end of each header tank. Further, a bracket having the positioning pin is fixed to the cap. In the heat exchanger, the flat tubes and corrugated fins are alternately laminated and brazed to each other. Also, the flat tubes and the header tanks are brazed to each other.

In such a construction, a bracket having a positioning pin is fitted to the end of a header tank to which a cap is fitted. Therefore, it is necessary to fix the cap and the bracket to the header tank, respectively and hence requires costs in terms of both of the number of parts and the number of assembling steps. Moreover, to fix the positioning pin to the bracket, the positioning pin is made to abut on the bracket and then is brazed to the bracket. Hence, there are cases where faulty brazing occurs and where the positioning pin is dropped or deformed by a load applied at the time of positioning the heat exchanger onto the vehicle body.

Further, in a construction such that the bracket supporting the positioning pin is fixed to the main body of a heat exchanger by brazing, in a brazing step is also presented a problem that the bracket is deformed with the deformation of the main body of the heat exchanger, causing the deformation of the positioning pin, that is, the slight inclination of the positioning pin.

SUMMARY OF THE INVENTION

The present invention is made in view of the foregoing matter, and it is an object of the present invention to provide a heat exchanger and a method of manufacturing the same, which has a structure capable of reducing the number of parts and the number of assembling steps, and properly fixing a positioning pin to a container.

According to an aspect, the heat exchanger has a core, a container, a pin, and a brazing material. The core has a plurality of tubes. The container has a tubular part and a cap part closing an end of the tubular part. The tubular part is located at an end of the core portion. The cap part is formed with a hole. The pin extends through the hole of the cap part along an axis of the container. The cap part and the pin are bonded to each other by the brazing material. Further, the heat exchanger has a preliminary fixing portion by which the pin is preliminarily fixed to the cap part before being bonded with the brazing material.

In the above construction, the pin is preliminarily fixed to the cap part before being bonded with the brazing material. As such, the number of parts and the number of assembling steps reduce, as compared with the conventional heat exchanger. Further, the pin can be properly fixed to the cap part without being dropped and deformed or displaced. Also, the quality of brazing between the pin and the cap part improves.

The method of manufacturing the heat exchanger includes arranging a container having a tubular part at an end of a core portion having tubes, inserting a pin into a hole of a cap part, preliminarily fixing the pin to the cap part and bonding the pin and the cap part by a brazing material at the same time as bonding the tubes and the tubular part.

In the above method, the pin is preliminarily fixed to the cap part before being bonded with the brazing material. As such, the pin is properly bonded to the cap part without increasing the number of parts and the number of assembling steps.

For example, the preliminary fixing is performed by deforming a portion of the pin such that the pin is supported by the cap part. As such, the method reduces costs and improves productivity. Alternatively, the preliminary fixing can be performed by deforming an end of the pin, the end projecting from the cap part into an inside of the container, such that a portion of the cap part is sandwiched between the deformed portion and another portion of the pin. As such, the pin is preliminarily fixed to the cap member by effectively using a projecting portion of the pin.

Further, the preliminary fixing can be performed by welding a portion between the cap member and the pin. Furthermore, the preliminary fixing can be performed by press-fitting the pin into the hole of the cap member. Accordingly, the pin is preliminary and properly fixed to the cap member with reduced costs and high productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:

FIG. 1 is a schematic plan view of a heat exchanger according to an embodiment of the present invention;

FIG. 2 is a partial enlarged end view of the heat exchanger when viewed along an arrow II in FIG. 1;

FIG. 3 is a cross-sectional view of a positioning pin of the heat exchanger taken along a line III-III in FIG. 2;

FIG. 4 is a schematic flow diagram showing a main process of manufacturing the heat exchanger according to the embodiment;

FIG. 5 is an explanatory view for explaining an example of a preliminary fixing step of the process according to the embodiment;

FIG. 6 is a schematic flow diagram showing a process of manufacturing the heat exchanger, in which a pin making step is added to the process of FIG. 4, according to the embodiment;

FIG. 7 is a schematic flow diagram showing a process of manufacturing the heat exchanger, in which a container making step is added to the process of FIG. 4, according to the embodiment;

FIG. 8 is a schematic flow diagram showing a process of manufacturing the heat exchanger, in which a pin crimping step is performed as an example of the preliminary fixing step, according to the embodiment;

FIG. 9 is a schematic diagram showing a process of manufacturing the heat exchanger, in which a pin welding step is performed as another example of the preliminary fixing step, according to the embodiment; and

FIG. 10 is a schematic diagram showing a process of manufacturing the heat exchanger, in which a pin making step is added in the process of FIG. 4 and a pin pressing-in step is performed as a pin inserting step and the preliminary fixing step.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENT

Hereinafter, an embodiment of the heat exchanger of the present invention will be described with reference to FIGS. 1 to 10.

The heat exchanger is for example employed as a condenser as a radiator for an air conditioner, as shown in FIG. 1. The present invention can be applied to other heat exchangers for an air conditioner or a heat exchanger for a vehicle such as a radiator for cooling a water of an internal combustion engine of a vehicle.

As shown in FIG. 1, the condenser has a plurality of condenser tubes 1 a through which refrigerant passes and corrugated condenser fins for facilitating heat exchange with the refrigerant. These condenser fins and condenser tubes 1 a are alternately stacked. Thus, the condenser fins and the condenser tubes 1 a construct a condenser core part 1. The outer surfaces of the condenser tubes 1 a are coated with a brazing material previously. Thus, the respective condenser fins are brazed to the adjacent condenser tubes 1 a by the brazing material as being heated.

Also, the condenser has a first tank 2 and a second tank 3 as containers on ends of the condenser core part 1. Namely, the first tank 2 and the second tank 3 are arranged at the ends of the condenser tubes 1 a and in communication with the condenser tubes 1 a. The second tank 3 is provided with a separation wall such that its inner space is divided into a first space and a second space in an axial direction thereof, e.g., in an up and down direction in FIG. 1. Also, an inner space of the first tank 2 is divided into a first and second space.

Further, a modulator pipe 5 is provided outside of the second tank 3. The modulator pipe 5 allows communication between a cooling portion and a supercooling portion that are formed in the condenser core part 1.

The first and second tanks 2, 3 and the modulator pipe 5 communicate with the insides of all condenser tubes 1 a. The first and second tanks 2, 3 and the modular pipe 5 extend in the direction of the width of the condenser core part 1, in other words, in a stacking direction of the condenser tubes 1 a and the condenser fins. Here, the stacking direction corresponds to the up and down direction in FIG. 1. The length of the first tank 2 and the second tank 3 is substantially equal to the width dimension of the condenser core part 1, the width dimension being measured in a direction parallel to the stacking direction.

As shown in FIG. 2, the first tank 2 is constructed of a tubular part 2 a and cap parts 6 covering on both ends of the tubular part 2 a. Similarly, the second tank 3 is also constructed of a tubular part (tubular part) 3 a and cap parts 6 provided on both ends of the tubular part 3 a.

The outer surfaces of the tubular parts 2 a, 3 a are coated with a brazing material. Likewise, the cap parts 6 are coated with a brazing material. Thus, the condenser tubes 1 a and the cap parts 6 are brazed to the tubular parts 2 a, 3 a by the brazing material as being heated.

Here, the cross sectional shape of the condenser tube 1 a is not limited to a special shape as long as the condenser tube 1 a allows refrigerant to pass through. For example, the condenser tube 1 a has a flat tubular shape including two generally flat walls, which are parallel to each other, and curved walls connecting the flat walls.

In the condenser, for example, the refrigerant discharged from a compressor (not shown) is introduced into the first space of the second tank 2. Then, the refrigerant is distributed into a first half section of the condenser core part 1. That is, the refrigerant is distributed into a half of the stacked condenser tubes 1 a. The refrigerant is collected into the first space of the second tank 3 and then introduced into the modulator pipe 5. In the modulator pipe 5, the refrigerant is separated into a gas-phase refrigerant and a liquid-phase refrigerant.

The liquid-phase refrigerant is introduced into the second space of the second tank 3 and further distributed into the remaining half of the condenser tubes 1 a. Further, the refrigerant is collected in the second space of the first tank 2 and then introduced to a decompression device (not shown).

The condenser core part 1 is provided with side plates as reinforcement members. The side plates are arranged at both sides (upper and lower ends in FIG. 1) of the condenser core part 1 across the whole length of the sides. Moreover, the first tank 2 and the modulator 5 are provided with brackets as fixing parts for fixing the condenser to the vehicle body. The brackets are formed with bolt holes.

The above condenser, as an example of the heat exchanger is constructed in such a way that the fixing parts provided on one side of the condenser can be freely fixed to and unfixed from a part of the vehicle by fastening or unfastening bolts and nuts. When the condenser is mounted to the part of the vehicle, the condenser needs to be positioned with respect to the part of the vehicle. Therefore, the condenser is provided with pins 4 for positioning to the part of the vehicle, as shown in FIG. 1. The pin 4 is for example arranged at one end of each tank 2, 3.

The pins 4 extend outside of the first tank 2 and the second tank 3 from the cap parts 6 in a direction parallel to the axis of the first tank 2 and the second tank 3. The extending portions of the pins 4 are received by the part of the vehicle, whereby the condenser is positioned. After the pins 4 are positioned, the fixing parts provided on the opposite sides of the pins 4 are fixed to the part of the vehicle by bolts and nuts. Accordingly, the condenser is mounted and fixed to the vehicle body. The above mounting and fixing structure is not limited to the condenser, but can be employed to other heat exchangers.

Next, the relationship between the pin 4 and the cap part 6 to which the pin 4 is fixed will be described with reference to FIG. 3. The pin 4 and the cap part 6 for the second tank 3 have the same relationship as the pin 4 and the cap part 6 for the first tank 2. That is, the pins 4 and the cap parts 6 are provided and coupled to the same manner between the first tank 2 and the second tank 3. Therefore, the description will be hereafter made about the pin 4 and the cap part 6 for the first tank 2 as an example.

The cap part 6 is a part for closing one end of the first tank 2 and has a hole 7 formed substantially in the center. The pin 4 has a shaft portion 4 b, a flange portion 9, an inserting portion 8 a, and a projecting portion 8. The shaft portion 4 b extends to outside of the first tank 2 in the axial direction of the first tank 2 for positioning when the pin 4 is coupled to the cap part 6. The flange portion 9 is positioned outside the cap part 6 when the pin 4 is coupled to the cap part 6. The flange portion 9 has a shape larger than the hole 7. The flange portion 9 has a first surface 9 a that faces outside and a second surface 9 b that faces an outer surface of the cap part 6.

The inserting portion 8 a is a part located within the hole 7 when the pin 4 is coupled to the cap part 6. The projecting portion 8 is positioned closer to the tip end of the pin 4 than the inserting portion 8 a. Namely, the projecting portion 8 is located on a side opposite to the flange portion 9 with respect to the inserting portion 8 a. The projecting portion 8 projects into the first tank 2 from an inner surface of the cap part 6. The projecting portion 8 is positioned closer to the tip of the pin 4 than the flange portion 9 and is positioned on a side opposite to the shaft portion 4 a, which projects outward from the cap part 6 for positioning.

The tubular part 2 a of the first tank 2 and the cap part 6 are separate parts and are bonded to each other by the brazing material with which the cap part 6 is coated previously. The cap part 6 has an edge portion 6 b bonded to the end surface of the tubular part 2 a and a recessed portion 6 a depressed inside the tubular part 2 a in the axial direction of the tubular part 2 a from the outer surface of the edge portion 6 b.

In a state where the pin 4 is fixed to the cap part 6, the pin 4 and the cap part 6 are in a relationship such that the first surface 9 a of the flange portion 9 is nearly flush with the outer surface of the edge portion 6 b. Namely, the amount of depression of the recessed portion 6 a, i.e., a distance between the outer surface of the recessed portion 6 a and the outer surface of the edge portion 6 b is substantially equal to a thickness of the flange portion 9.

Here, the condenser as an example of the heat exchanger has preliminary fixing means (preliminary fixing portion) for provisionally fixing the pin 4 to the cap part 6 before the pin 4 and the cap part 6 are finally bonded to each other by the brazing material. Namely, the pin 4 and the cap part 6 are preliminarily fixed to each other before bonded by the brazing material.

For example, the preliminary fixing means is means for provisionally fixing the pin 4 to the cap part 6 by deforming a portion of pin 4 to form a deformed portion such that the pin 4 is partly fixed to or partly engaged with the cap part 6. Also, the preliminary fixing means can be means for provisionally fixing the pin 4 to the cap part 6 by deforming the projecting portion 8 to form a deformed portion (clamp portion) for sandwiching or holding the cap part 6 between the deformed portion and the flange portion 9. Further, the preliminary fixing means can be means for provisionally fixing the pin 4 to the cap part 6 by forming a welding portion so as to partly bridge the cap part 6 and the pin 4. Moreover, the preliminary fixing means can be means for provisionally fixing the pin 4 to the cap part 6 by pressing (press-fitting) the pin 4 into the hole 7 to form a press-fitted portion.

Next, a process of manufacturing the condenser will be described with reference to FIGS. 4 to 10. FIG. 5 is a sectional view to show an example of a preliminary fixing step (e.g., press-fitting step) in the process of manufacturing the condenser.

FIG. 4 shows a main process of manufacturing the condenser. The main process includes a container arranging step (S100), a pin inserting step (S200), the preliminary fixing step (S300), a cap arranging step (S400), and a bonding step (S500). The process shown in FIG. 4 can also be applied to manufacture another heat exchangers having pins for positioning.

First, at a step S100, the condenser core part 1 is assembled by alternately arranging the condenser tubes 1 a and the condenser fins. Also, the side plates are arranged on both sides of the condenser core part 1 for reinforcement, and the first tank 2 and the second tank 3 are arranged at both ends of the condenser core part 1. In this condition, the cap parts 6 to which the pins 4 are fixed are not arranged to the first tank 2 and the third tank 3 yet.

Next, in a step S200, the pins 4 are inserted into the holes 7 of the cap parts 6. At this time, the projecting portion 8 of the pin 4 is inserted into the hole 7 from the side on which the recessed portion 6 a is formed. That is, the projecting portion 8 of the pin 4 is inserted along a direction denoted by an arrow A in FIG. 3. The pin 4 is inserted to the cap part 6 until the second surface of the flange portion 9 is brought into contact with the outer surface of the recessed portion 6 a. Thus, the projecting portion 8 projects from the inner surface of the cap part 6, as shown in FIG. 3.

Here, the pin inserting step S200 and the container arranging step S100 may be reversed in the order because the respective steps handle separate parts. In other words, the pin inserting step S200 may be performed before the container arranging step S100 or both steps S100, S200 may be performed at the same time.

Then, in a step S300, the pin 4, which has been inserted to the cap part 6, is provisionally or preliminarily fixed to the cap part 6. Examples of this preliminary fixing step include a deforming step shown in FIG. 8, a welding step shown in FIG. 9, and the press-fitting step shown in FIG. 10. The examples of the preliminary fixing steps will be described later.

In a step S400, the cap parts 6 on which the pins 4 are provisionally fixed are arranged at the ends the first tank 2 and the second tank 3. Next, in a step S500, the condenser as assembled is put in a furnace. Thus, the brazing material previously applied to the respective parts is melted, thereby fusing the respective parts. Accordingly, the pins 4 are bonded to the cap parts 6 at the same time as bonding the condenser tubes 1 a to the first tank 2 and the second tank 3 with the brazing material.

By the brazing step S500, the pins 4, which had been provisionally fixed to the cap parts 4, are securely bonded to the cap parts 6 without being tilted and the cap parts 6 are bonded so as to close the openings of the ends of the first tank 2 and the second tank 3. Accordingly, the pins 4 function as pins for positioning the condenser to the part of the vehicle.

In the above, the cap parts 6 and the tubular parts 2 a, 3 a are provided as separate parts and bonded to each other at the bonding step S500. However, in a case that each tank 2, 3 is constructed of a container integrally having the cap part 6 and the tubular part 2 a, 3 a, the cap arranging step S400 is not performed.

The above process shown in FIG. 4 can further has a pin forming step S150, as shown in FIG. 6. In the step S150, the pin 4 having the shaft portion 4 b, the flange portion 9, the inserting portion 8 a and the projecting portion 8 as shown in FIG. 3 is formed. The pin making step S150 is performed, for example, by aluminum die casting. Then, in the pin inserting step S200, the pin 4 made in this manner is inserted to the hole 7 of the cap part 6 such that the flange portion 9 is positioned in the recessed portion 6 a on the outside of the cap part 6 and the inserting portion 8 a is positioned within the hole 7. Here, the pin making step S150 can be performed before the container arranging step S100.

Moreover, the process shown in FIG. 4 can further has a container forming step S50, as shown in FIG. 7. In the step S50, the cap parts 6 and the tubular parts 2 a, 3 a are separately formed. The tubular parts 2 a, 3 a can be formed, for example, by extruding. The cap parts 6 formed in the container making step S50 are arranged at the ends of the tubular parts 2 a, 3 a in the cap arranging step S400 after the pin inserting step S200 and the preliminary fixing step S300. Then, in the brazing step S500, the cap parts 6 a are bonded to the tubular parts 2 a, 3 a by the brazing material previously coated on the surfaces of the respective parts. In the process of FIG. 7, the pin forming step S150 of FIG. 6 can be also included.

Next, examples of the preliminary fixing step S300 will be described with reference to FIG. 5 and FIGS. 8 to 10.

First, as shown in FIG. 8, the preliminary fixing step can be performed by deforming a part of the pin 4. In a step S300 a, a part of the pin 4 is deformed so that the pin 4 is fixed to or engaged with the cap part 6. For example, the projecting portion 8 of the pin 4 can be deformed to expand radially outward. Thus, the perimeter of the hole 7 of the cap part 6 is sandwiched or held between the deformed portion of the projecting portion 8 and the flange 9. As a method for deforming the projecting portion 8 can be used a method for hitting the projecting portion 8 by a hammer or the like or for crushing the projecting portion 8 by a press or the like. Alternatively, a part of the pin 4 can be deformed in another manner as long as the pin 4 can be preliminary fixed to or held by the cap part 6.

Next, as shown in FIG. 9, the preliminary fixing step can be performed by welding. In a step S300 b, a portion between the pin 4 and the cap part 6, which are coupled to each other in the step S200, is welded so as to bridge therebetween. In the welding of step S300 b, the cap part 6 and the pin 4 are bonded by applying heat or pressure, or both of heat and pressure to them so that a continuous bonding portion is formed between the cap part 6 and the pin 4, i.e., the pin 4 is partly continuous to the cap part 6. Alternatively, the welding can be performed by adding an appropriate fusing material to them. For example, the pin 4 and the cap part 6 can be bonded to each other by fusion welding, press welding, or brazing and soldering.

Further, as shown in FIG. 10, the preliminary fixing step can be performed by pressing in (press-fitting). In the process of FIG. 10, the pin forming process S150 a is added to the process of FIG. 4, and the pin inserting step S200 and the preliminary fixing step S300 are replaced into a press-fitting step S300 c.

In the step S150 a, a pin 4A having a shaft portion 4 a, a flange portion 9, a projecting portion 10 is made. As shown in FIG. 5, the shaft portion 4 a extends on a first side 9 a of the flange portion 9. The projecting portion 10 extends on a second side 9 b of the flange portion 9. The flange portion 9 has the shape larger than the hole 7 of the cap member 6.

Further, the projecting portion 10 has a taper shape. Namely, a size (e.g., diameter) of the projecting portion 10 reduces toward a tip end of the projecting portion 10. Also, the size of the projecting portion 10 is set such that the projecting portion 10 can not fully pass through the hole 7 unless a load larger than a predetermined level is not applied to the pin 4. Namely, the load larger than the predetermined level is required to insert the projecting portion 10 into the hole 7 up to a position that the second side 9 b of the flange 9 contacts the recessed portion 6 a.

Namely, an end 10 a of the projecting portion 10 has an outer size smaller than the bore size of the hole 7 and a base portion (inserting portion) 10 b of the projecting portion 10, which connects to the flange portion 9, has an outer size slightly larger than the bore size of the hole 7.

Then, in the step 300 c, the pin 4A is press-fitted to the cap part 6 while inserting into the hole 7. Specifically, the projecting portion 10 is inserted into the hole 7 and further press-fitted to the hole 7 of the cap part 6 up to a position that the second side 9 b of the flange portion 9 is brought into contact with the outer surface of the recessed portion 6 a of the cap part 6. When the second side 9 b of the flange portion 9 is brought into contact with the outer surface of the recessed portion 6 a, the perimeter of the hole 7 makes close contact with the base portion 10 b of the projecting portion 10 and is further expanded outward in the radial direction further than the initial size.

As described above, the heat exchanger exemplary as the condenser is so constructed as to include: the core part 1 having the plurality of tubes 1 a and the plurality of fins alternately stacked; the first tank 2 and the second tank 3 each of which has the tubular part 2 a, 3 a arranged on one end of the condenser core part 1 and has the cap part 6 for closing the end of the tubular part 2 a, 3 a; the pins 4, 4A inserted into the holes 7 of the cap parts 6 and extending in the axial direction of the first tank 2 and the second tank 3 from the cap parts 6; the brazing material for brazing the cap parts 6 to the pins 4, 4A; and the preliminary fixing means (preliminary fixing portion) for provisionally fixing the cap parts 6 to the pins 4, 4A before bonding them with the brazing material, or, in a state where the brazing material is not applied to them. According to this construction, members such as plates or brackets for holding the pins 4, 4A are not required and the positioning of the pins 4, 4A with respect to the cap parts 6 is stabilized. As such, the number of parts and the number of man-hours or assembling steps can be reduced. Further, the separation and deformation of the positioning pins 4, 4A can be reduced.

Moreover, the pins 4, 4A are positioned outside the cap parts 6 and have the flange portions 9 larger than the holes 7, the inserting portions 8 a, 10 a positioned within the holes 7, and the projecting portions 8, 10 projecting into the first tank 2 and the second tank 3 from the cap parts 6, respectively. When this construction is adopted, the shapes of the outer peripheral surfaces in the axial direction of the pins 4, 4A contribute to the stabilizing of the positions of the cap parts 6 and the pins 4, 4A at the time of preliminary fixing. Hence, this can enhance a provisional fixing work and a brazing quality.

Further, the cap parts 6 and the tubular parts 2 a, 3 a can be separate parts and are bonded to each other by the brazing material, respectively. Also, the cap parts 6 have edge portions 6 b bonded to the end surfaces of the tubular parts 2 a, 3 a and the recessed portions 6 a recessed inside from the end surfaces of the tubular parts 2 a, 3 a, respectively. The first surfaces 9 a of the flange portions 9 are nearly flush with the outer surfaces 6 b of the cap parts 6, respectively. In other words, the first surface 9 a of the flange portions 9 coincides with the outer surfaces 6 b of the cap parts 6 in the axial direction of the pins 4, 4A In this construction, the positions of the cap parts 6 and the pins 4, 4A at the time of preliminary fixing are stabilized. Hence, this can enhance a provisional fixing work and a brazing quality. Moreover, since the area of a rubber mounting base when the condenser is mounted in the vehicle can be secured, wear of rubber can be reduced. With this, resistance to vibration improves.

Also, the preliminary fixing portion is defined by the deformed portion formed by deforming a portion of the pin 4. Accordingly, the preliminary fixing portion can be provided at high productivity without increasing costs.

The pin 4 has the projecting portion 8 projecting through the hole 7 and the preliminary fixing portion is provided by the deformed portion formed by deforming the projecting portion 8. The pin 4 is preliminary fixed to the cap part 6 by holding the cap part 6 between the deformed portion and the flange portion 9. Accordingly, the preliminary fixing portion having a higher holding force can be provided by utilizing the projecting portion 8.

When the preliminary fixing portion is provided by the welding portion for bridging the cap part 6 and a portion of the pin 4, more reliable provisional fixing can be performed. Further, when the preliminary fixing means is provided by the press-fitted portion formed by press-fitting the pin 4A into the hole 7, provisionary fixing of low cost and high productivity and having an excellent holding force can be performed.

In the method of manufacturing a heat exchanger, the first tank 2 and the second tank 3 having the tubular parts 2 a, 3 a are arranged on the respective ends of the core part 1 having the plurality of tubes 1 a. Also, the pins 4, 4A are preliminarily fixed to the cap parts 6 by inserting into the holes 7 formed in the cap parts 6. Further, the tubes 1 a are bonded to the tubular parts 2 a, 3 a of the first tank 2 and the second tank 3 by the brazing material. At the same time, the pins 4, 4A are bonded to the cap parts 6 by the brazing material. By this method, the number of parts and the number of man-hours or assembling steps are reduced. Also, the separation or drop of the pins 4, 4A from the cap parts 6 and the deformation of the pins 4, 4A are reduced.

The method can further include the step of forming the pins 4, 4A to have the flange portions 9 larger than the holes 7, the inserting portions 8 a, 10 a to be inserted into the holes 7, and the projecting portions 8, 10 further extending from the inserting portions 8 a, 10 a. The pins 4, 4A are inserted to the holes 7 of the cap parts 6 such that the flange portions 9 are located outside the cap parts 6 and the inserting portions 8 a, 10 a are located within the holes 7, respectively. In this method, in the step of inserting the pins 4, 4A into the respective holes 7, the shapes of the outer peripheral surfaces in the axial direction of the pins 4, 4A enhance stability in the positional relationship between the cap parts 6 and the pins 4, 4A. Thus, preliminary fixing is performed with reliability. Hence, this method enhances a brazing quality.

Further, the method can further include the step of forming the first tank 2 and the third tank 3. Namely, the cap parts 6 and the tubular parts 2 a, 3 a are formed as separate parts. The cap parts 6 are brazed to the tubular parts 2 a, 3 a at the same time as bonding the tubes la to the tubular parts 2 a, 3 a and the pins 4, 4A to the cap parts 6 in the step of bonding by the brazing material. In this method, the cap parts 6 to which the pins 4, 4A are preliminarily fixed are arranged to and bonded to the tubular parts 2 a, 3 a. As such, the quality of preliminary fixing can be stabilized and productivity can be enhanced.

In the step of preliminary fixing, the portion of the pin 4 is deformed so as to be fixed to the cap part 6. Accordingly, the preliminary fixing can be performed at high productivity without increasing costs.

In inserting the pin 4 to the hole 7 of the cap part 6, the pin 4 is inserted in such a way that a portion of the pin 4 passes and projects through the hole 7 to provide the projecting portion 8. Then, in preliminary fixing, the projecting portion 8 is deformed so that the cap part 6 is held between the deformed portion of the projecting portion 8 and the flange portion 6. In this method, the preliminary fixing portion having a sufficient holding force can be formed by utilizing the projecting portion 8.

Alternatively, in the step of preliminary fixing, a portion between the cap part 6 and the pin 4 can be welded to each other so as to bridge between them. As such, the reliability of provisional fixing improves.

Also, in the step of the preliminary fixing, the pin 4A having the tapered projecting portion 10 can be press-fitted to the hole 7 of the cap part 6. In this case, the inserting step and the preliminary fixing step can be performed simultaneously. As such, the preliminary fixing having a sufficient holding force can be performed without increasing costs.

Here, the shapes of the pins 4, 4A are not limited to the illustrated examples of FIGS. 3 and 5. The pins 4, 4A can have other shapes as long as these can be preliminarily and stably fixed and sufficiently serve as the positioning pins.

Further, the above structures and methods can be also employed to heat exchangers other than the condenser for the vehicle air conditioner.

The example embodiments of the present invention are described above. However, the present invention is not limited to the above example embodiments, but may be implemented in other ways without departing from the spirit of the invention. 

1. A heat exchanger, comprising: a core having a plurality of tubes; a container having a tubular part and a cap part, the tubular part arranged at an end of the core and defining an axis, the cap part closing an end of the tubular part and defining a hole; a pin extending through the hole of the cap part along the axis of the tubular part; a brazing material bonding the pin and the cap part; and a preliminary fixing portion by which the pin and the cap part are preliminarily fixed before being bonded with the brazing material.
 2. The heat exchanger according to claim 1, wherein the container is in communication with the tubes.
 3. The heat exchanger according to claim 1, wherein the preliminary fixing portion is defined by at least one of a portion of the pin and a portion of the cap part.
 4. The heat exchanger according to claim 1, wherein the pin has a flange portion, an insertion portion and a projecting portion, the flange portion is located on an outer side of the cap part and having a dimension larger than that of the hole of the cap part, the insertion portion is located within the hole of the cap part, and the projecting portion projects to an inside of the container from an inner side of the cap part.
 5. The heat exchanger according to claim 4, wherein the cap part and the tubular part are separate members and bonded to each other with the brazing material, the cap part defining an edge portion bonded to an end surface of the end of the tubular part and a recessed portion recessed from the edge portion to the inside of the tubular part more than the end surface of the end of the tubular part, the edge portion defining an outer surface, the flange defining a first surface and a second surface opposite to the first surface, and the flange is received in the recessed portion such that the first surface faces the cap part and the second surface substantially coincides with the outer surface of the edge portion in an axial direction of the tubular part.
 6. The heat exchanger according to claim 1, wherein the preliminary fixing portion is defined by a deformed portion of the pin.
 7. The heat exchanger according to claim 4, wherein the projecting portion of the pin includes a deformed portion on a side opposite to the flange portion with respect to the insertion portion, and the deformed portion and the flange portion hold a portion of the cap part therebetween, thereby defining the preliminary fixing portion.
 8. The heat exchanger according to claim 1, wherein the pin and the cap part partly have a welded portion between them as the preliminary fixing portion.
 9. The heat exchanger according to claim 1, wherein the preliminary fixing portion is defined by a perimeter of the hole and a portion of the pin that is fitted within the hole.
 10. A method of manufacturing a heat exchanger, comprising: arranging a container having a tubular part at an end of a core having a plurality of tubes; inserting a pin into a hole of a cap part; preliminarily fixing the pin to the cap part; and bonding the pin to the cap part with a brazing material at a same time as bonding the tubes to the tubular part.
 11. The method according to claim 10, further comprising: forming the pin to have a flange portion defining a first surface and a second surface and having a dimension larger than that of the hole of the cap part, an insertion portion adjacent to the first surface of the flange portion and a projecting portion extending from the insertion portion, wherein in the inserting, the flange portion of the pin is arranged such that the first surface faces the cap part and the insertion portion is arranged within the hole.
 12. The method according to claim 11, wherein the cap part has an edge portion defining an end surface and a recessed portion recessed from the end surface of the edge portion, and in the inserting, the flange portion is received in the recessed portion such that the second surface of the flange portion substantially coincides with the end surface of the edge portion.
 13. The method according to claim 10, further comprising: forming the tubular part and the cap part as separate members, wherein in the bonding, the tubular part and the cap part are bonded to each other with the brazing material.
 14. The method according to claim 10, wherein in the preliminary fixing, a portion of the pin is deformed so that the pin is fixed to the cap part.
 15. The method according to claim 10, wherein in the inserting, the pin is inserted such that a portion of the pin extends through the hole of the cap part and projects from the cap part, and in the preliminary fixing, a portion of the pin projecting from the cap part is deformed such that the cap part has a portion held between a deformed portion of the pin and another portion of the pin.
 16. The method according to claim 10, wherein in the preliminary fixing, the cap part and the pin are partly welded.
 17. The method according to claim 10, wherein in the inserting and the preliminary fixing, the pin is press-fitted into the hole of the cap part. 